There is known a vertical power MOSFET (metal oxide semiconductor field effect transistor) including a trench gate electrode provided inside a trench and a field plate electrode provided below the trench gate electrode.
Here, the trench gate electrode and the field plate electrode have different optimal pitch dimensions. Thus, there is proposed a power MOSFET in which trenches with a long depth dimension for providing a trench gate electrode and a field plate electrode, and trenches with a short depth dimension for providing a trench gate electrode, are alternately provided in parallel.
However, alignment for separately forming the trench with a long depth dimension and the trench with a short depth dimension is difficult. Thus, there is room for improvement from the viewpoint of productivity.